Sanatana Dharma: eternal truth; dharma also means righteousness, religion, duty, justice, or morality
Vedanta: literally, the culmination of the Vedas; most often refers to the philosophy given by the Upanishads, the Brahma Sutra, and the Bhagavad Gita

Vedas: literally, knowledge; most often refers to the Samhitas (Rig, Yajur, Sama, and Atharva Vedas)
Apaurushaya: literally, not of man; a description of the Vedas, denying human authorship and indicating divine realization universally experienced
Upanishads: literally, that which destroys ignorance; the philosophical portion of the Vedas
Shruti: literally, sound; most often refers to the Vedas, including the Samhitas, Aryanakas, and Brahmanas, which contain the Upanishads; sometimes strictly interpreted as the Samhitas alone

Brahman: the Supreme Being; ultimate Truth beyond time, space, and causation
Atman: the Self, or the Soul; our true nature which is ultimately the same as Brahman
Satchitananda: sat - existence, chit - consciousness, ananda - bliss; a description of Brahman

Maya: the superimposing force that gives name and form to the objects of the world as we know it; ignorance
Nama: name
Rupa: form
Yoga: to join (with God/Divinity/Truth)
Marga: path

Karma: action; the actions and consequences, which one has acquired over one's life and past lives
Samskaras: more specific term for the actions and consequences, which one has acquired over one's life and past lives
Jnana: knowledge, wisdom
Bhakti: devotion, love

Moksha, Mukthi: freedom; enlightenment; realization; removal of ignorance; release from samsara
Samsara: the cycle of rebirth, including both joy and sorrow